A bias generator refers to a generator providing a bias such as a bias voltage of a bias current. For instance, a bias voltage may be the voltage applied to an electronic component in order to switch this component on or off or controlling an amount of current passing through the electronic component. Depending on the nature of electronic component, the bias voltage may be positive or negative. For example, a bias voltage may be applied to a control terminal of a transistor, such a base or a gate terminal, causing the transistor to become conductive or controlling an amount of current passing through the transistor. The bias may be used to set a DC operating voltage of a transistor. In turn the transistor may amplify an AC input signal properly.
Bias generators may be used with different types of circuits such as signal amplifiers, operational amplifiers and voltage to current convertors. Conventional bias generators for use with single ended low noise amplifier, (LNA) include a first stage for providing a first bias voltage and a second stage for providing a second bias voltage. The amplifier is formed by two transistors in a cascode configuration, in which an input transistor receives the first bias voltage and another transistor receives the second bias voltage. However, in such systems the drain to source voltage of the input transistor varies with temperature affecting the gain and reliability of the amplifier.